Dawes boost controller installation advice - PeachParts Mercedes-Benz Forum

JHZR2 · #1 01-22-2004, 06:22 PM

Hi,

Installed my dawes boost controller today. I can definitely feel the difference, I certainly was suffering from a tired wastegate.

I have a few installation hints, which I hope will be useful, since I think that probably has been the best $48 Ive spent on my car.

A few things:

-I was worried about using vacuum tees down there, especially the fact that Id have to block off one end. They were nearly impossible to find in the right size, so what worked best is what was mentioned by someone on another thread... Cut a short length of vacuum tubing (MB OEM is best because its slightly thicker than the equivalent spec tubing sold on fastlane). Slide that tube onto the barbed ends on the controller. This new setup will fit just inside the 9mm ID wastegate hose, and then can be held tightly together with small hose clamps that can be found for 79c at home depot.

-DO NOT set your controller pressure with a mityvac. I read a post on another thread of someone that didnt have a boost gauge in their old saab, and they set it with a mityvac. Well let me just say this. I have a new mityvac silverline. Used it twice. Attached it all up to the boost controller, and adjusted the controller length so that it would vent at 11.25 or so PSI. I installed it on my car, thinking I wouldnt have to mess with it again. The first time I accelerated on the highway, the pressure went to over 15psi at the intake manifold! I had to dial it way far out through a couple trials on the shoulder of the interstate before I could get it to 11.5 psi, and thats where Ive left it.

Overall the car drives much nicer, and for whatever odd reason, shifts smoother as well. Turbo spooling is considerably faster, and acceleration from a dead stop is much better (not that it was bad before, itll just pull to 4k rpm much quicker and easier now). When driving at highway speed, pressure is normal when crusing (5psi at 60 mph on flat ground). However, with the tap of the pedal, the boost will go almost instantly to 10-11 psi. Before when my max was 8-9, it took 2-3 times longer to reach that full boost whenI pressed the pedal.

I seem to notice that the car is a bit noisier now. Its almost as if it has a bit more of a gowl to the ehaust note.

So thats my report. I only wish darren dawes would make his controller with a little bit larger barbs, so it could be a direct splice into our wastegate lines, which are 9mm ID. I cant imagine any turbo has a wastegate line as small as the holes on the ends of his controller.

JMH

81Wagon · #2 01-22-2004, 07:18 PM

Thanks for the tips! I'll be doing this in a couple weeks myself...

I have to wonder though if holding one hose inside another is the best idea. It seems like it might slip out unless you clamp it fairly tight, at which point you might be constricting the air flow (perhaps the reason you saw more pressure after installation than with the mityvac).

I'll give it a try though, since it's worked for you!

JHZR2 · #3 01-22-2004, 07:32 PM

The barb is pretty sturdy brass, I dont think that it would get smaller.

One issue that you kind of are alluding to is that the ID of the tube used on the mity vac was much smaller than the wastegate hose. Perhaps that extra volume between the pressure source (turbo or mityvac) and the controller valve is wwhat caused my readings and settings to be messed up.

One way or another, Id install it at the correct setting and adjust it on the car from there.

JMH

1stimer · #4 01-22-2004, 07:48 PM

Where did you put the gauge?

JHZR2 · #5 01-22-2004, 09:26 PM

It had a bracket. I used the screw on the far right side of the kick panel below the steering wheel, through the bracket and into the regular holder that the screw tightens into. The screw is long enough to go through a thin metal bracket and still hold everything tight.

JMH

vwbuge · #6 01-22-2004, 11:07 PM

I got mine from JC WHtiney. Don't laugh, it works good and it is illuminated.

JHZR2 · #7 01-22-2004, 11:15 PM

Mine is placed in the kickpanel screw directly above where vwbuge's is. Rotate his gauge 90 degrees to the left, and screw it into the existing screwhole. I didnt want to make any new holes, otherwise Id probably do it his way. It will allow a bit more room for the leg, although Ive never scraped on mine..

JMH

1stimer · #8 01-22-2004, 11:17 PM

I'm 6'7" and my knees would have that thing knocked out the first day I bet.

JHZR2 · #9 01-22-2004, 11:21 PM

Im 6'5, mine is installed with a bit less space (as explained in my last post), and I have about an inch clearance, no matter how I put my knees (unless Im loking to tap it, but thats not comfortable for me to sit). So Id bet the setup, especially vwbuge's setup could take someone as tall as 6ft 7.

And thats one of the great things about these cars... Being able to stretch my legs while driving

JMH

wolf_walker · #10 01-22-2004, 11:59 PM

Quote:

Originally posted by JHZR2

And thats one of the great things about these cars... Being able to stretch my legs while driving

JMH

Love my 123, but it's still got nothing on my 78 Lincoln for cabin space!

Nifty install.. I'm contimplating the economy gauge to boost gauge deal if I can lay hands on one.

#11 01-23-2004, 12:14 AM

If I was to install a boost gauge, I would stick it on the steering column...

wbain5280 · #12 01-23-2004, 05:17 AM

Look for a pod to mount on the A-Pillar. It's in sight and out of the way, of your knees.

rbmercedes · #13 01-23-2004, 06:08 PM

My dad installed a boost guage in a plate that takes the place of the coin tray just in front of the shifter after intercooling his 300SD.

Happy Motoring

RBM

JHZR2 · #14 01-23-2004, 10:30 PM

Quote:

Originally posted by wbain5280
Look for a pod to mount on the A-Pillar. It's in sight and out of the way, of your knees.

The problem I had with the A pillar was, how do you set it up so that you dont see all the unsightly pressure lines going into the gauges? I wanted to mount mine there, but then when I look into my windshield, Id see the pressure fitting on the back of the gauge.

Not a big deal in reality, but still something that turned me off to putting it there.

JMH

81Wagon · #15 01-28-2004, 08:55 PM

JHZR2 - I installed my boost controller today; once I started doing it I realized the way I initially visualized it was way off and now your setup makes fine sense to me (and it was easy, too!).

I stuck my boost gauge in one of the center vents (an EGT gauge occupies the other).